-import cPickle
-import errno
-import os
+# $Id$
+# $URL$
+
+"""A few things that didn't seem to fit anywhere else."""
+
+import os, os.path
import pwd
import tempfile
+import fcntl
+import errno
import threading
+import subprocess
import logger
+PID_FILE = '/var/run/nodemanager.pid'
-PID_FILE = '/var/run/node_mgr.pid'
+####################
+def get_default_if():
+ interface = get_if_from_hwaddr(get_hwaddr_from_plnode())
+ if not interface: interface = "eth0"
+ return interface
+def get_hwaddr_from_plnode():
+ try:
+ for line in open("/usr/boot/plnode.txt", 'r').readlines():
+ if line.startswith("NET_DEVICE"):
+ return line.split("=")[1].strip().strip('"')
+ except:
+ pass
+ return None
+
+def get_if_from_hwaddr(hwaddr):
+ import sioc
+ devs = sioc.gifconf()
+ for dev in devs:
+ dev_hwaddr = sioc.gifhwaddr(dev)
+ if dev_hwaddr == hwaddr: return dev
+ return None
+
+####################
+# daemonizing
def as_daemon_thread(run):
"""Call function <run> with no arguments in its own thread."""
thr = threading.Thread(target=run)
os.setsid()
if os.fork() != 0: os._exit(0)
os.chdir('/')
- os.umask(0)
+ os.umask(0022)
devnull = os.open(os.devnull, os.O_RDWR)
- for fd in range(3): os.dup2(devnull, fd)
-
-def deepcopy(obj):
- """Return a deep copy of obj."""
- return cPickle.loads(cPickle.dumps(obj, -1))
+ os.dup2(devnull, 0)
+ # xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
+ crashlog = os.open('/var/log/nodemanager.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
+ os.dup2(crashlog, 1)
+ os.dup2(crashlog, 2)
def fork_as(su, function, *args):
"""fork(), cd / to avoid keeping unused directories open, close all nonstandard file descriptors (to avoid capturing open sockets), fork() again (to avoid zombies) and call <function> with arguments <args> in the grandchild process. If <su> is not None, set our group and user ids appropriately in the child process."""
try:
os.chdir('/')
close_nonstandard_fds()
- pw_ent = pwd.getpwnam(su)
- os.setegid(pw_ent[3])
- os.seteuid(pw_ent[2])
+ if su:
+ pw_ent = pwd.getpwnam(su)
+ os.setegid(pw_ent[3])
+ os.seteuid(pw_ent[2])
child_pid = os.fork()
if child_pid == 0: function(*args)
except:
os.seteuid(os.getuid()) # undo su so we can write the log file
os.setegid(os.getgid())
- logger.log_exc()
+ logger.log_exc("tools: fork_as")
os._exit(0)
else: os.waitpid(child_pid, 0)
+####################
+# manage files
def pid_file():
- """We use a pid file to ensure that only one copy of NM is running at a given time. If successful, this function will write a pid file containing the pid of the current process. The return value is the pid of the other running process, or None otherwise."""
+ """We use a pid file to ensure that only one copy of NM is running at a given time.
+If successful, this function will write a pid file containing the pid of the current process.
+The return value is the pid of the other running process, or None otherwise."""
other_pid = None
if os.access(PID_FILE, os.F_OK): # check for a pid file
handle = open(PID_FILE) # pid file exists, read it
write_file(PID_FILE, lambda f: f.write(str(os.getpid())))
return other_pid
-def write_file(filename, do_write):
+def write_file(filename, do_write, **kw_args):
"""Write file <filename> atomically by opening a temporary file, using <do_write> to write that file, and then renaming the temporary file."""
- os.rename(write_temp_file(do_write), filename)
+ os.rename(write_temp_file(do_write, **kw_args), filename)
-def write_temp_file(do_write):
+def write_temp_file(do_write, mode=None, uidgid=None):
fd, temporary_filename = tempfile.mkstemp()
+ if mode: os.chmod(temporary_filename, mode)
+ if uidgid: os.chown(temporary_filename, *uidgid)
f = os.fdopen(fd, 'w')
try: do_write(f)
finally: f.close()
return temporary_filename
+
+# replace a target file with a new contents - checks for changes
+# can handle chmod if requested
+# can also remove resulting file if contents are void, if requested
+# performs atomically:
+# writes in a tmp file, which is then renamed (from sliverauth originally)
+# returns True if a change occurred, or the file is deleted
+def replace_file_with_string (target, new_contents, chmod=None, remove_if_empty=False):
+ try:
+ current=file(target).read()
+ except:
+ current=""
+ if current==new_contents:
+ # if turns out to be an empty string, and remove_if_empty is set,
+ # then make sure to trash the file if it exists
+ if remove_if_empty and not new_contents and os.path.isfile(target):
+ logger.verbose("tools.replace_file_with_string: removing file %s"%target)
+ try: os.unlink(target)
+ finally: return True
+ return False
+ # overwrite target file: create a temp in the same directory
+ path=os.path.dirname(target) or '.'
+ fd, name = tempfile.mkstemp('','repl',path)
+ os.write(fd,new_contents)
+ os.close(fd)
+ if os.path.exists(target):
+ os.unlink(target)
+ os.rename(name,target)
+ if chmod: os.chmod(target,chmod)
+ return True
+
+
+####################
+# utilities functions to get (cached) information from the node
+
+# get node_id from /etc/planetlab/node_id and cache it
+_node_id=None
+def node_id():
+ global _node_id
+ if _node_id is None:
+ try:
+ _node_id=int(file("/etc/planetlab/node_id").read())
+ except:
+ _node_id=""
+ return _node_id
+
+_root_context_arch=None
+def root_context_arch():
+ global _root_context_arch
+ if not _root_context_arch:
+ sp=subprocess.Popen(["uname","-i"],stdout=subprocess.PIPE)
+ (_root_context_arch,_)=sp.communicate()
+ _root_context_arch=_root_context_arch.strip()
+ return _root_context_arch
+
+
+####################
+class NMLock:
+ def __init__(self, file):
+ logger.log("tools: Lock %s initialized." % file, 2)
+ self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+ flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+ flags |= fcntl.FD_CLOEXEC
+ fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+ def __del__(self):
+ os.close(self.fd)
+ def acquire(self):
+ logger.log("tools: Lock acquired.", 2)
+ fcntl.lockf(self.fd, fcntl.LOCK_SH)
+ def release(self):
+ logger.log("tools: Lock released.", 2)
+ fcntl.lockf(self.fd, fcntl.LOCK_UN)
git://git.onelab.eu / nodemanager.git / blobdiff